Seminole County, Florida
A shallow water table limits basements on 63% of Seminole County's mapped land, a higher share than 76% of US counties. Shrink-swell clay limits houses without basements on 4%.
None of the county is in drought on the October 13, 2026 Drought Monitor map, after 3% a week earlier. FEMA's flood data list 957 flood losses here since 2016, 2% of them in buildings with basements. 29% of homes were built before 1980, against 50% nationally; the median home dates from 1988.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Seminole County
| Expansive clay (limits slab homes) | 4.4% |
| High water table (limits basements) | 63.2% |
| Septic fields very limited | 76.3% |
| Clay swell (LEP, by area) | 1.6% |
| High-swell land (LEP 6%+) | 4.4% |
| Urban land, not rated | 9.2% |
| Mapped soil | 220,800 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Basinger | 11% | n/a |
| Myakka | 8% | 100% |
| EauGallie | 7% | n/a |
| Astatula | 6% | n/a |
| Tavares | 4% | n/a |
| Nittaw | 4% | n/a |
How we count · survey areas FL117 (2025-08-28)
What the numbers mean here
On 63% of Seminole County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 44.34 in, 6.96 in below the 1991-2020 average year of 51.30 in.
USDA rates 76% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 37 of the last 52 weeks; the most was 100% of its area, in 19 weeks, most recently on the June 30, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 8.2% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
957 flood losses since 2016, $48.8 million paid. The worst year was 2022, with 615. Foundations of the buildings, where recorded: 2% basements, 82% slabs, 5% crawl spaces, 11% elevated. Median water depth outside the building: 12 in.
| Year | Flood losses |
|---|---|
| 2016 | 11 |
| 2017 | 213 |
| 2018 | 6 |
| 2019 | 4 |
| 2020 | 6 |
| 2021 | 9 |
| 2022 | 615 |
| 2023 | 4 |
| 2024 | 79 |
| 2025 | 8 |
| 2026 to date | 2 |
Rain
| Average year, 1991-2020 | 51.30 in |
| 12 months to August 2026 | 44.34 in (-6.96) |
| 2025 | 46.27 in (-5.03) |
| Wettest year since 1895 | 1953: 70.15 in |
| Driest year since 1895 | 2000: 31.09 in |
| Days with 1 inch or more, normal at SANFORD (12 mi away) | 16.9 |
Homes
| Housing units | 199,565 |
| Median year built | 1988 |
| Built before 1980 | 29% |
| Built 2000 or later | 28% |
| Owner-occupied | 66% |
| Median value, owner-occupied | $386,900 |
| Single-family detached | 61% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Orange County, FL | 17 mi | 1% | 72% |
| Volusia County, FL | 26 mi | 3% | 74% |
| Lake County, FL | 35 mi | 4% | 51% |
| Brevard County, FL | 38 mi | 3% | 78% |
| Osceola County, FL | 44 mi | 1% | 88% |
| Flagler County, FL | 55 mi | 6% | 93% |
| Sumter County, FL | 57 mi | 2% | 77% |
| Polk County, FL | 62 mi | 6% | 68% |
Sources: USDA SSURGO (August 28, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status